A Ofdm-mfsk Underwater Acoustic Communication Technology Based on Packet Signal-to-Noise Ratio Confidence

An OFDM-MFSK and underwater acoustic communication technology, which is applied in the field of OFDM-MFSK underwater acoustic communication technology based on the confidence of the packet signal-to-noise ratio, can solve the loss of sub-carrier signal-to-noise ratio, frequency selective fading, and equalization technology can not obtain relatively It can improve the diversity signal gain, improve the application performance, and improve the system performance loss.

Active Publication Date: 2020-12-22
HARBIN ENG UNIV
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AI Technical Summary

Problems solved by technology

Severe multipath spreading in the time domain of the channel is manifested as severe frequency selective fading in the frequency domain. When the effective subcarrier of the multi-carrier system is located at the deep fading frequency of the channel, the signal-to-noise ratio of the subcarrier will be seriously lost , conventional equalization techniques still cannot achieve better results

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  • A Ofdm-mfsk Underwater Acoustic Communication Technology Based on Packet Signal-to-Noise Ratio Confidence
  • A Ofdm-mfsk Underwater Acoustic Communication Technology Based on Packet Signal-to-Noise Ratio Confidence
  • A Ofdm-mfsk Underwater Acoustic Communication Technology Based on Packet Signal-to-Noise Ratio Confidence

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Embodiment Construction

[0038] The present invention will be described in more detail below in conjunction with the accompanying drawings.

[0039] The present invention mainly comprises the steps:

[0040] (1) The transmitter performs 2-diversity modulation on the information, and adds the end of a frame of data to the chirp signal;

[0041] (2) The receiving end detects the frame preamble signal, completes data interception and Doppler factor estimation, and performs Doppler compensation on the received data;

[0042] (3) Demodulate each data symbol, and combine the diversity signals according to the combination method of the group signal-to-noise ratio confidence;

[0043] (4) Finally, demodulate the data after diversity combining.

[0044] The transmitting end performs 2-diversity modulation on the information, and adds the end of a frame of data to the chirp signal. The 2-diversity modulation of information refers to dividing all N subcarriers into two diversity branches, namely subcarrier [1...

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Abstract

The invention provides an OFDM-MFSK underwater acoustic communication technology based on packet signal to noise ratio (SNR) confidence coefficient. A transmitting end performs two-diversity modulation on the information and adds chirp signals at the head and the tail of one frame of data; a receiving end performs detection on a frame preamble signal to finish the data interception and the doppler factor estimation, and performs the doppler compensation on the received data; the demodulation is performed on each data symbol, and the diversity signals are combined according to a combining way of the packet SNR confidence coefficient; and finally the demodulation is performed on the data after the diversity combination. By using the frequency diversity technology, the performance loss caused by the channel serious frequency selectivity influence of the OFDM-MFSK underwater acoustic communication system is effectively compensated, and the SNR of the combined signal is improved by proposing the diversity signal combination way based on the packet SNR confidence coefficient.

Description

technical field [0001] The invention relates to the field of underwater acoustic channels, in particular to an OFDM-MFSK underwater acoustic communication technology based on the confidence level of the packet signal-to-noise ratio. Background technique [0002] OFDM-MFSK is a modulation technology that combines multi-carrier technology and MFSK. The transmitting end of OFDM-MFSK divides all subcarriers into groups of M elements, uses MFSK to map information, and the receiving end uses a non-coherent method. MFSK signal detection is performed without channel estimation and equalization process. OFDM-MFSK is compatible with the high communication rate of multi-carrier modulation technology, and retains the robust performance of MFSK modulation. Compared with Orthogonal Frequency Division Multiplexing (OFDM) modulation, it can better balance the transmission rate and robust performance. [0003] The underwater acoustic channel is one of the most complex wireless channels so f...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26H04B13/02
CPCH04B13/02H04L27/2627H04L27/2656H04L27/2691
Inventor 孙大军郑翠娥崔宏宇张居成韩云峰王永恒
Owner HARBIN ENG UNIV
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